Electric-arc lamp



(No Model.)

B. FORD ELECTRIC ARC LAMP.

No 515,205. Patented Feb. 20, 1894;

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UNITED STATES PATENT OFFICE.

BRUCE FORD, OF J OHNSTOWVN, PENNSYLVANIA.

ELECTRIC-ARC LAM P.

SPECIFICATION forming part of Letters Patent No. 515,205, dated February 20, 1 894. Application filed December 8, 1892. Serial No. 454,434. (No model.)

To aZZ whom it may concern.-

Be it known that I, BRUCE FORD, residing at J ohnstown, in the county of Cambria and State of Pennsylvania, have invented an Improvement in Electric-Arc Lamps, of which the following is a specification.

My invention has reference to are lamps and consists of an improved arc lamp which is fully set forth in the following specification, and shown in the accompanying drawings.

The object of my invention is to provide an arc lamp in which the automatic release for the feed carbon is operated electrically, without the necessity of a train of gears, also to provide a construction whereby the carbon itself may be released from its support, instead of releasinga rod or support to which the carbon is attached.

In carrying out my invention, I keep the feed carbon or rod supporting same firmly bound to the regulating lever (whose motion adjusts length of arc) by the pressure of a spring, but when the carbon has burned away to the limit of the regulator, an electromagnet is automatically put into circuit, which attracts the binding spring, thereby raising it and permitting the carbon to drop.

Referring to the drawings, Figure 1. is asectional view of an arc lamp adapted to my im provement. Fig. 2 is a detail view in side elevation of the parts to which my invention has particular reference, and shows the electrical connections thereof. Fig. 5. is a plan view of the same.

A. is the box inclosing the mechanism and may be made of any suitable material, preferably of cast iron.

B. is the feed carbon and O. the fixed carbon.

P. is a tube inclosing the movable carbon B for the purpose of keeping it always in proper alignment. Alignment of the two carbons is obtained by means of the swivel D.

E. is a metal yoke supporting the fixed carbon O and is itself supported by, but insulated from, the box A. B. might also represent a rod supporting the carbon at the lower extremity.

F. is a reflector for diffusing the light emitted from the are below it.

Within the box A. I have the compound solenoid G, shown in section, which may be of any of the familiar forms used in the arc lamps of commerce. It comprises two coils, one (g) of coarse wire connected in series with the arc, and one of fine wire wound in opposition to coil g and connected as a shunt to the arc. The action of the series coil g upon core H. is to open the arc, while that of the shunt coil g tends to close it.

In the normal operation of the lamp the proper length of arc is obtained when the core H is balanced between the two coils.

K. is a dash pot preventing vibration and sudden movements of the core H. in either direction.

J is the regulating lever connected to the core 11 by the connecting rod 1. To the lever J. but insulated from it, is attached the metal brush L arranged to always give electric contact to the carbon 13, without having itself tension enough to prevent the full motion of the carbon, up or down, with relation to the lever J. 1

M. is a spring fixed to lever J. but insulated therefrom and rests, normally against the carbon B. with sufficient tension to prevent any motion relative to lever J. The tube P is cut away on both sides to allow brush L and spring M to come unobstructed into contact with carbon 13.

As the solenoid, performing its duty of regulating the length of the arc, moves the core H. up or down it is evident that the lever connected to it must move and with it the carbon 13., bound to the lever between the spring M. and the brush L, and thus change the length of the are at the extremity of carbon B. The core H however can only move a limited distance, so that, as the carbon burns away, and the core becomes lower until its limit of motion is reached, it is obvious that one or both of the carbons must be released sufficiently to allow them to approach near enough for the regulatorto again come into use. It is my design to operate this release by electric means as follows:-- To the lever J, I attach an electromagnet 0. whose armature N. is fastened to the spring M as shown. One of the terminals of this magnet is fastened to the spring M thus putting it in electric connection with the carbon 13.; the other terminal is attached to a I small contact point f. on the under side of the lever. As the arc burns away the carbons, the regulator lowers the lever J till its limit is reached when the point f. comes in contact with f. on the head of the yoke E connected to carbon C. Magnet is, thus connected as a shunt to the arc and at once attracts its armature N pulling spring M. away from carbon B, allowing the latter to drop. But as soon as spring M looses its hold of carbon B the circuit of magnetO is broken at point X and the springinstantly flies back, having allowed the carbon to drop only a very small distance. If the regulator has not by this time separated points f and f the release continues to act until regulator does separate them.

The pole of magnet 0 may be hollowed out, as shown by the dotted lines, to partially receive its armature though this is not essential.

The magnet could, instead of releasing the carbon itself, release a rod or support towhich carbon was attached, though I prefer the re-' lease as shown on account of simplicity.

R. is a cap, by removing which old carbon may be replaced with new one.

a. and B. are the-binding posts for the arc.

S. and S. are eyes by which the lamp may be suspended.

It is immaterial to my invention, considered broadly, what the minor details of construction may be as they could easily be altered to suit special requirements though in all cases the principle would remain the same, that is to say, the release would be actuated by electro-magnetic means. It could also be arranged so that the magnet would normally bind the carbon instead of actuating the re lease, and when the circuit of magnet was its circuit breaker mounted on a clutch lever,

the magnet being disengaged when the clutch is holding the carbon and the circuit is broken.

2. In an electric arc lamp, the combination with a regulating solenoid of an automatic catch for the movable carbon attached to the regulator lever; a make and break contact located in a circuit shunted from the carbons, and mechanically connected with the solenoid; and an electromagnet and spring mounted on said contact lever, the spring normally bearing against the movable carbon to hold itin place.

3. In an arc lamp the combination with solenoid regulator G.H.,ot the lever J friction spring M., carbon 13., the tube P. to keep carbon aligned, and magnet 0 to actuate release for carbon B, all substantially as described.

In testimony whereof I have affixed my signature in presence of two witnesses.

BRUCE FORD.

Witnesses:

HENRY S. KAINES, WM. A. DONALDSON. 

